Adjustment to the diagnosis and treatment of breast cancer is a complex process that unfolds over time, with medical, psychological, social, and functional factors impacted differentially through the continuum of care and follow-up. Women with breast cancer commonly report feeling overwhelmed by having to integrate large amounts of medical information and having to make decisions about treatment benefits, as well as immediate and long-term impact on their quality of life. There is an urgent need to develop and test interventions that mitigate psychosocial distress, provide guidance through treatment decision-making, and address the myriad cultural and logistical barriers to care that exist especially for low-income women with breast cancer. The Breast CARES program is proposed to specifically meet this need. The overall goal of this R21 proposal is to address a national priority in cancer control research by developing and conducting a feasibility study of a new and innovative model of an interdisciplinary case management program for underserved women with newly diagnosed breast cancer, including those who are Spanish-speaking. Three specific aims will guide this exploratory study: (1) design an interdisciplinary case management program, integrating two additional elements-on-site navigation and counselor-initiated telephone calls--into the traditional nurse-oriented case management model, for patients at strategic points before, during and after breast cancer treatment; (2) conduct a feasibility study of the Breast CARES program, using a one-group, intervention-only research design with specific focus on process evaluation, in the setting of an urban "safety net" health care system; and (3) utilize these essential process evaluation data to prepare and submit a research proposal for a large Phase III multi-institution randomized clinical trial to test the efficacy, cost-effectiveness, and exportability of this comprehensive information, navigation and psychosocial support program.